Re: [PATCH RFC 05/77] PCI/MSI: Convert pci_msix_table_size() to a public interface

Alexander Gordeev
2013-10-08T07:56:59Z

On Mon, Oct 07, 2013 at 02:10:43PM -0400, Tejun Heo wrote:
> On Wed, Oct 02, 2013 at 12:48:21PM +0200, Alexander Gordeev wrote:
> > Make pci_msix_table_size() to return a error code if the device
> > does not support MSI-X. This update is needed to facilitate a
> > forthcoming re-design MSI/MSI-X interrupts enabling pattern.
> >
> > Device drivers will use this interface to obtain maximum number
> > of MSI-X interrupts the device supports and use that value in
> > the following call to pci_enable_msix() interface.
>
> Hmmm... I probably missed something but why is this necessary? To
> discern between -EINVAL and -ENOSPC? If so, does that really matter?

pci_msix_table_size() is kind of helper and returns 0 if a device does
not have MSI-X table. If we want drivers to use it we need return -EINVAL
for MSI-X incapable/disabled devices. Nothing about -ENOSPC.

> tejun

--
Regards,
Alexander Gordeev
agordeev@redhat.com